Add option to adjust thumbnail caption's menu icon size.
Code refactoring: Move workspace thumbnail adding/removing from dockedWorkspace.js 
to myThumbnailsBox.js.

This keeps the relevant thumbnail code together in one file making it easier to 
maintain.
Code Refactoring: Rename myThumbnailsBox.js to myWorkspaceThumbnail.js.

This helps associate the code with Gnome's workspaceThumbnail.js.
Code refactoring: Move caption code from myWorkspaceThumbnail.js into a separate class 
file (thumbnailCaption.js).
Override Gnome Shell's overview workspace geometry calculations (workspacesView.js).

Issues:
The current workspace overview geometry calculations fail to take into account a 
dock on a secondary display or a dock wider than the default. Thus, window 
thumbnails end up overlapping the dock in activies overview mode in those situations.
Code Cleanup: Update js object declarations with Gnome gjs class.
Thumbnail windowclone not properly disconnecting signals from app realwindow.

Details:
We can't use the windowclone's source on the parent window because we've reverted to using the realWindow texture to fix a previous bug where the parent window disappeared when a modal dialog was opened (see commit 82a2099da4eb1fcb7485b91b4a18e8fa97bf561c).
Fail to remove taskbar icon when minimized window is closed.
Code cleanup: myWorkspaceThumbnails.js & thumbnailCaption.js.
Code cleanup: Remove margins from tab labels in prefs.js.
Add experimental favorites shortcut panel to dock.
Add shortcut button popup menu options.

Details:
Option to show the shortcut button popup menu arrow at the top
Option to hide thumbnails when the shortcut button popup menu is shown
Reworked code for shifting the dock when the message tray is visible (Copied from Dash-To-Dock).
Begin Gnome 3.14 port.
Merge develop branch (Gnome 3.14 port)